Motor assembly



June 9, 1942.

E. D. BOISSELI ER MOTOR ASSEMBLY Filed Oct. 25, 1958 Patentecl June 9, 1942 MOTOR ASSEMBLY Earl D. Boisselier, Glen Ellyn, 111., assignor, by mesne assignments, to Earl Products Company, Chicago, 111., a corporation of Illinois Application October 25, 1938, Serial No. 236,953

2 Claims.

This invention relates to motor assemblies for use in connection with engraving apparatus, and more particularly to a motor assembly for use with a so-called tapping tool especially adapted for making stippled designs in light sheet metal or similar surfaces.

One of the objects of the invention is to provide a construction which includes a novel motor assembly possessing special features of construction which lend themselves to standard manufacturing practices, and thereby make it possibl to provide a relatively inexpensive, substantial, and highly efficient unit.

A further object of the invention is to provide a construction in which the novel motor assembl may be readily combined with a handle which not only constitutes a housing for the motor, but at the same time affords convenient means for gripping and manipulating the tool.

With the above and other objects in view which will more readily appear as the nature of the invention is better understood, the same consists in the novel construction, combination and arrangements of parts hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawing, in which:

Figure 1 is a side elevation of the improved motor assembly.

Figure 2 is an enlarged vertical section of the improved motor assembly.

Figure 3 is a detail sectional view of the top portion of the motor assembly taken at right angles to Figure 2.

Figure 4 is a top plan view of the motor assembly shown in Figures 2 and 3.

Figure 5 is a diagrammatic view illustrating the electric circuit employed.

Figure 6 is a detail perspective view of the improved motor assembly.

Similar reference characters designate corresponding parts throughout the several figures of the drawing.

According to the embodiment of the invention shown in the drawing, the same includes in its organization a hollow handle A made of wood or other insulating material, and the tapping unit B. This unit has rigid therewith a cap or cup portion C which is preferably of stamped metal, and closes the lower end of the handle. That is to say, this cap or cup member C is intended to receive the reduced end portion A of the handle or casing A as shown by dotted lines in Figure 2. Moreover, said cup is also provided with openings C which permit of air circulation within the handle or casing A, and with a central bottom opening I for receiving the reduced end portion 2 of a stud 3.

The said reduced portion of the stud may be riveted or peened or otherwise turned over the edges of the metal of the cap surrounding the opening I to rigidly fasten the stud 3 to the cap. In that connection, it will also be observed that the reduced portion 2 of the stud passes through a suitable opening in the transverse web portion 4 of a frame which includes the upstanding arms 55. Thus, when the reduced portion 2 of the stud 3 is passed through the transverse member of the frame and the opening I of the cap, and riveted or peened as indicated at 2a; the stud, the frame, and the cap will all be rigidly locked together as one piece.

The-stud 3 is provided with a central opening or bore 3a which serves as a guide for the shank. of a tool such as a tapping point or pin P. Thev upper portion of the opening or bore 3a in the: stud is enlarged as indicated at 312 to provide a. chamber or socket for a coil spring 6 which surrounds the upper portion of the pin P adjacent.-

a solenoid type armature member I. Since the. spring 6 is confined between the bottom of the:- socket in the stud and the underside of the solenoid type armature, it will be apparent that the said armature 1 as well as the pin P will normally be urged upwardly in the bore of the stud.

Acoil 8 surrounds the stud and armature, the said coil being positioned between the arms 55 of the frame. As will be apparent from Figure 2, the upper portions of the arms 5-5 are extruded inwardly as indicated at 9 to engage the top of a coil 8 and hold it in position. In assembling, the inherent resiliency of the arms 55 permits them to be spread apart sufliciently to permit the coil 8 to be moved over the armature I and the stud 3. When the coil is in place the arms 55 may be drawn together, thus bringing the extruded portions 9 into overlying and holding engagement with the upper end of the coil.

With further reference to the upper portions of the arms 55, it may be pointed out that the same are provided with suitable slots [0 for receiving a transverse insulation piece II. This insulation piece is provided with a central opening [2 to clear the armature pin or insulation element I3 carried by the upper end of the armature 1. This insulation bridge piece constitutes an abutment or stop for the armature 1, thus limiting the upward movement of the armature under the force of the spring 6, and preventing the armature pin from unduly punishing the contacts, later referred to.

Moreover, it will be observed that the upper extremities of the arms -5 are bent inwardly as indicated at I4 and provided with relatively narrow tongues l5 which in turn provide shoulders for supporting a top insulation disc 16. The extremities of the tongues I5 are twisted so as to pull the entire fibre plate or disc l6 against the shoulders formed at the base of the tongues I5.

The insulation disc I6 carries a pair of spring contacts i8 and I9. The contact 18 is connected with the coil 8 by the lead l8a shown in Figure 3a and the contact 19 is connected with the line wire 20. The coil 8 has its other terminal connected with the line-wire 2| as will be seen from Figures 3 and 5.

As shown in Figure 2, the points of the contacts l8 and 19 will be normally held in engaged relation by the pressure exerted through the insulation element I3 carried by the solenoid or armature l which is urged upwardly by the spring 6. Thus, when the line wires 20' and 2| are plugged into a service outlet, the circuit will be completed through the coil 8 and thus pull the armature 1 toward the center of the coil. When the armature is thus pulled downwardly, the insulation element l3'will be moved away from the contacts I8 and I9 and the latter will spring apart or separate as shown in Figure 5 thus breaking the circuit. As soon as the circuit is broken the spring 6 will again exert its influence to move the armature 1 upwardly and in turn press the point of the spring contacts i8 and I9 together as shown by the dotted lines in Figure 5, and also by full lines in Figure 2.

The above described electrical operation is repeated as long as the tool is connected in circuit with a source of alternating current supply. The result of the electrical action is to produce a rapid vibration of the tapping point P so that when the tip of the point is held close to a surface to be stippled, said surface will be impressed l with a plurality of indentations of greater or less depth, according to the distance that the operator holds the tip of the point from the surface to be stippled.

From the foregoing, it will be apparent that the, present invention provides an engraving tool with a novel tapping unit which may be easily fabricated and assembled, and which may be completely wired so that the line wires may be pulled through the hollow handle A and the cap or cup C of the unit will thereby be pulled into engagement with the reduced end portion A of the handle to complete the assembly of the device and properly encase or house the tapping unit.

I claim:

1. A tool operating reciprocating motor assembly comprising a solenoid coil, a tool actuating armature reciprocable in said coil, mounting means for said coil comprising a pair of arms means on said arms to secure the coil between said arms, spring means tending constantly to urge said armature in one direction relative to said coil, said coil being effective, when energized, to move said armature in the opposite direction relative to said coil, an insulating disc held by said arms in fixed relationship to said coil and limiting movement of said armature by said spring means, an insulating strip held .by said arms in fixed relationship to said coil, a switch controlling supply of current to said coil, said switch comprising a pair of contacts carried by said insulating strip, a yieldable mounting for at least one of said contacts tending constantly to urge it away from the other contact, and means whereby said armature, when urged against said stop means by said spring means, holds said yieldably mounted contact engaged With the other contact thereby completing the coil circuit, and releases said yieldably mounted contact to permit it to separate from the other contact when the coil is energized and the armature thereby is moved against said spring means.

2. A tool operating reciprocating motor assembly comprising a stud having an interior bore and a spring receiving socket, and also reduced in external diameter at one end, a frame including a pair of arms connected by a transverse portion having an opening, a cup also having an opening, the openings of the transverse portion of the frame and the cup registering and fitting over the reduced end of the stud, a rivet portion formed at the extremity of the reduced end of the stud to lock the cup and frame to the stud, a coil fitted over the stud and embraced by said arms, inwardly directed portions on the arms for engaging one end of the coil to hold it in the arms, an armature in the coil and having a tool portion extending through said bore of the stud, a spring in the socket of the stud tending constantly to urge the armature in one direction relative to said coil, a switch mounted on said arms and controlling supply of current to said coil, said switch comprising a pair of contacts carried by a support mounted on said arms, a yieldable mounting for at least one of said con tacts tending constantly to urge it away from the other contact, and means whereby said armature, when urged against said stop means by said spring means, holds said yieldably mounted contact engaged with the other contact, thereby completing the coil circuit, and releases said yieldably mounted contact to permit it to separate from the other contact when the coil is energized and the armature thereby is moved against said spring means.

EARL D. BOISSELIER. 

